Amazon Elastic Container Service (ECS) introduced zone-aware routing for Service Connect, automatically directing service-to-service communications to endpoints within the same Availability Zone (AZ). This reduces cross-AZ data transfer costs and latency without compromising resilience. The routing dynamically adjusts based on endpoint scaling and health, preserving load balance across healthy zones and maintaining high availability.
This routing is enabled by default for new and existing ECS services after a one-time redeployment and requires no application code changes or additional infrastructure. Customers can monitor cross-AZ traffic patterns using Amazon VPC Flow Logs enriched with AZ metadata to verify routing effectiveness. The feature is available at no extra cost in all AWS commercial and GovCloud regions supporting ECS Service Connect.
Source & further reading
Amazon ECS Service Connect now supports Zone-Aware routing ↗Source published 2026-07-23. This report was prepared with AI assistance from the linked primary-source material. Claims and limitations should be checked against the original announcement or research.